1. Field of the Invention
The present invention relates to integrated circuit (IC) devices, and in particularly, to a guard ring structure for an IC device and a method for forming the same.
2. Description of the Related Art
In a semiconductor process, a plurality of dies, each containing integrated circuits (ICs), are fabricated on a semiconductor wafer at one time. Advances in semiconductor processing technologies, such as high-resolution photolithography and anisotropic plasma etching, have dramatically reduced the feature sizes of formed semiconductor devices in the integrated circuit and increased the device packing density. Other process technologies, such as die scribing for separating dies within a wafer and fuse blowing for improving the yield of circuit elements in the ICs, however, induce lateral stresses which spread along boundaries of the die. The lateral stresses may further progress into a core circuitry of the die, thus reducing yield and performance thereof. In addition, oxidation of the ICs in the die induced by environment moisture also reduces yield and performance thereof.
Therefore, a guard ring structure is needed to be formed around a semiconductor die for the purposes of moisture isolation and structural reinforcement of the ICs therein.